List of islands of County Mayo

Additionally, areas of ecological significance related to both offshore and freshwater islands, designated by the National Parks and Wildlife Service, are also listed.

Those north of Clew Bay such as Achill and the islands off the Mullet Peninsula are generally of ancient Dalradian age, similar to County Donegal and the Grampian Highlands.

Geologically, the Clew Bay islands themselves are the youngest in the county, formed during the Lower Carboniferous about 350 million years ago.

Records from the 1841 Census show that 47 of County Mayo's offshore islands were inhabited, with a combined population of approximately 10,000.

[8] Today, the islands are recognised by the State as an integral part of Ireland's national heritage, preserving the remnants of a unique aspect of Irish culture.

Communities had resided on these islands for generations, and their remains can still be seen to this day through the villages, stone walls and lazybeds which they left behind.

In contrast, Achill benefitted from a bridge to the mainland which allowed the population to temporarily rebound, reaching its all-time peak in 1911.

In recent times, the islands have become a popular tourist destination and depend heavily on the tourism and hospitality sector.

Popular activities include surfing, sailing, island-hopping in Clew Bay, spiritual retreats and eco-tourism.

The list below is not exhaustive, and includes named offshore islands that are either extensive (typically greater than 2 acres in area) or in someway locally significant or identifiable.

Freshwater islands have played an important role in the county's history and host an abundance of castles, monasteries, church ruins and unspoiled woodlands.

Many of the county's offshore and freshwater islands are designated as areas of ecological significance and are protected both at national and European level.

Mayo's offshore islands are a haven for wildlife and biodiversity, supporting hundreds of species of bird, fish and marine mammal, as well as unique vegetation.